It is known in the brewing industry that some hop acids can inhibit the growth of the microorganisms that can cause spoilage in beer. For example, the Todd Jr. et al. U.S. Pat. No. 5,082,975 discloses that the hop acid, hexahydrolupulone, can inhibit the growth of certain Lactobacillus. In addition, the recently issued Millis et al. U.S. Pat. No. 5,286,506 discloses that solid food products can be protected from food pathogens, including Listeria monocytogenes, by incorporating beta-acids, which are extracted from hops, into such food products.